The present invention relates to a sheet finishing apparatus by which image formed sheets delivered from an image forming apparatus main body are ejected by a sheet delivery means and are placed on a sheet delivery tray, and to an image forming apparatus.
A sheet finishing apparatus is used as an apparatus by which a plurality of image formed sheets delivered from the image forming apparatus main body are stacked as a bundle of sheets and stapled by a stapling means. Further, as the sheet finishing apparatus, there is an apparatus which has a function conduct various processes, such as a shift assorting process, an arrangement process, a punching process, a bookbinding process, or the like, except the stapling processing.
To the sheet finishing apparatus, the image forming apparatus such as a copier, printer, facsimile device, or the like, and the function are connected, and the sheet finishing apparatus is driven corresponding to the sequence operation of a copy or print process.
The sheet finishing apparatus conducts sheet finishing such as stapling processing, shift separation processing, or arrangement processing, onto the received sheets, and after that, the processed sheets are delivered onto the sheet delivery tray.
Incidentally, relating to the sheet finishing apparatus, the structure in which each kind of sheet is conveyed to a finishing processing section and brought into contact with a stopper means, is already disclosed in each of Japanese Tokkaisho No. 60-142359, 60-158463, 62-239169, 62-288002, 63-267667, Tokkaihei No. 2-276691, 8-319054, and Tokkohei No. 5-41991.
The image formed sheet conveyed into the sheet finishing apparatus is conveyed by a conveying means, and after that, reversely conveyed onto an intermediate stacker, and a trailing edge portion of the sheet is brought into contact with a stopper means, and stopped at a predetermined position. At this stop position, a plurality of sheets are successively conveyed and stacked, and the trailing edge portions are aligned. After the sheet finishing such as stapling is conducted on the bundle of sheets whose trailing edge portions are aligned, the bundle of sheets is delivered on the delivery sheet tray outside the apparatus by a sheet delivery means.
As the sheet delivery means of the sheet finishing apparatus, the following mechanisms are known.
(1) A sheet finishing apparatus in which the sheet is conveyed to the finishing section by a winding ring, and brought into contact with the stopper means, and only at the time of sheet delivery, the sheet delivery roller is lowered and the bundle of sheets is delivered.
(2) A sheet delivery means in which the intermediate stacker is arranged at a steep inclination angle, and the sheet is conveyed to the finishing section by the free dropping of the sheet, and is brought into contact with the stopper means, and the sheet delivery roller is operated up and down by using an engagement mechanism, and at the time of the delivery of the bundle of sheets, the bundle is delivered when the pressing force is applied onto the sheet delivery roller by using a solenoid.
(3) A sheet finishing apparatus in which a vertical force automatic changing apparatus is provided on the sheet delivery means, and the vertical force to obtain the higher holding force, is applied when the bundle of sheets in which a plurality of sheets are stapling processed, is delivered, rather than when one sheet is delivered. (Japanese Tokkaihei No. 8-217323).
Any sheet finishing apparatus of the above, is difficult to stabilize the sheet conveyance property for the sheets having every characteristics, and there is a possibility that the influence of the curl of the sheet or the static electricity is exerted. Further, there is also a problem that the mechanism is complicated and the production cost is increased.
The first object of the present invention is to improve the above problem in the conventional sheet finishing apparatus, and to provide a sheet finishing apparatus in which the sheet arrangement performance is increased, and a sheet delivery means having a simple structure is provided, and an image forming apparatus.
Incidentally, the image forming apparatus written in Japanese Tokkaihei No. 3-277591 is structured such that it has the first stapling mode in which one position of the end portion of the recording sheet is stapled, and the second stapling mode in which 2 positions in the vicinity of the center of the recording sheet are stapled, and respective positions at predetermined dimensions are arbitrarily inputted and set, and stapled, without depending on the size of the recording sheet.
In the conventional sheet finishing apparatus, when the first stapling processing in which one position is slantingly stapled at the end portion of the sheet, and the second stapling processing in which 2 position in the vicinity of the center of the recording sheet are stapled in parallel, can be selectively conducted for each kind of sheets of large or small sizes, the exclusive use driving means for respectively moving a pair of left and right staple means linearly and rotationally are necessary.
That is, the first driving means for linearly moving the pair of left and right staple means respectively in parallel to a predetermined position, and the second and the third driving means for respectively rotating the pair of left and right staple means by a predetermined angle in order to slantingly staple, are provided in the apparatus. Accordingly, in order to drive these driving means, at least 3 exclusive use driving motors and the control means for controlling these driving motors are necessary.
Accordingly, the number of component members of the driving motors, driving means, and control means is increased, the structure becomes complicated, and the assembling manhours are increased, and the production cost is increased.
Further, when a pair of left and right stapling means are arranged in parallel, and 2 positions in parallel are stapled, the minimum interval of the parallel stapling is limited by the dimension of the width of the staple means.
Further, in the conventional sheet finishing apparatus, because a plurality of driving motors and a plurality of driving means are necessary, the apparatus becomes complicated, and the production cost is increased.
Accordingly, the second object of the present invention is to provide a sheet finishing apparatus in which the assembling adjustment operation or maintenance operation can be easily and quickly conducted by the simplification of the staple processing component members of the sheet finishing apparatus, and a decrease of the production cost is attained.
In the sheet finishing apparatus to attain the first object, in which, after the image formed sheet is conveyed by a conveying means of the sheet finishing apparatus, the sheet is stacked on an intermediate stacker, and after the sheet is finished by the finishing means, the sheet is delivered by the sheet delivery means and stacked onto the sheet delivery tray, the sheet delivery means has: a sheet delivery roller composed of a sheet delivery upper roller and a sheet delivery lower roller by which the sheet can be nipped and conveyed and delivered, and which can be rotated positively and reversely; and a contact pressure means for oscillating the sheet delivery upper roller and enabling the roller to come into pressure-contact with the sheet delivery lower roller and to separate from it; and a driving means whose drive source is a driving motor which can be positively and reversely rotated, and which drive the sheet delivery upper roller and the sheet delivery lower roller, and the pressure contact means.
Further, the image forming apparatus to attain the first object is provided with the sheet finishing apparatus.
In the sheet finishing apparatus to attain the second object, in which, after the image formed sheet delivered from the image forming apparatus main body is conveyed and stacked and arranged on the intermediate stacker, 2 portions or one portion of the sheet are staple processed by the staple means, the apparatus is structured by: one staple means slantingly arranged in the conveyance direction of the sheet; the sheet finishing apparatus main body which movably supports the staple means on the inclined surface; and the driving means composed of one drive source which linearly moves the staple means in the direction perpendicular to the conveyance direction of the sheet and rotationally moves the staple means in the vicinity of the corner portion of the sheet, wherein the parallel staple processing to 2 portions of the sheet in parallel to the direction perpendicular to the conveyance direction of the sheet, and the slanting staple processing to one portion in the vicinity of the corner portion of the sheet, are conducted by the one slantingly arranged staple means.